Airtac SAILB Rear Lock Cylinder SAILB40X75
The AirTAC Airtac SAILB Rear Lock Cylinder SAILB40X75 is a genuine double-acting ISO 15552 profile cylinder with a Ø40mm bore, 75mm stroke and a built-in spring-applied, air-released mechanical lock in the back cover — it holds the load at the retracted (rod-in) stroke end even when air is lost.
- BoreØ40 mm
- Stroke75 mm
- Port sizeG1/4
- Lock positionBack cover
- Rod threadM12×1.25
- UnlockAir + manual
About the Airtac SAILB Rear Lock Cylinder SAILB40X75
The AirTAC SAILB40X75 is a double-acting ISO 15552 profile cylinder featuring a spring-applied, air-released mechanical lock housed in the back cover. Because the lock engages at the retracted stroke end, it secures your load safely in the rod-in position whenever release air is cut, delivering reliable power-loss safety. In this 40mm bore class, it generates 879N of push force and 528N of pull force at 0.5 MPa.
Unlike a plain SAI cylinder, this model physically holds the rod without relying on live air pressure. The lock is released automatically by supplying air to the release port, or manually via the override lever. Note that the variable air cushion at the locker end is shorter (20mm) compared to the free end (27mm), a deliberate design choice to accommodate the locking mechanism within the end cap.
Airtac SAILB Rear Lock Cylinder SAILB40X75 Technical Specifications
| Model | Airtac SAILB Rear Lock Cylinder SAILB40X75 |
|---|---|
| Series | SAIL ISO 15552 cylinder with lock |
| Bore size | Ø40 mm |
| Stroke | 75 mm |
| Acting type | Double acting, with lock |
| Port size | G1/4 |
| Rod thread | M12×1.25 |
| Lock type | Spring-applied, air-released (back cover) |
|---|---|
| Unlock | Automatic (air) & manual |
| Operating pressure | 0.15 – 1.0 MPa |
| Temperature | -20 to +70 °C |
| Speed range | 30 – 800 mm/s |
| Cushion | Adjustable (27 mm free end / 20 mm lock end) |
| Max stroke | Up to 1200 mm |
Specifications follow the official AirTAC SAIL datasheet (ISO 15552). Confirm against the product label before installation. Port options: PT / G.
How the Lock Holds
The lock is spring-applied and air-released: a spring drives a lock pin into the rod when the release air is removed, so the load is held at the retracted (rod-in) stroke end without live pressure. Supply air to the release port to unlock automatically, or use the manual release lever.
The lock engages only when the piston reaches the stroke terminal on the back-cover side — it is a static end-of-stroke hold, not a mid-stroke clamp and not a moving-rod brake. For locking at any position along the stroke, choose a BSAI clamp-lock instead.
Theoretical Output Force (Ø40mm)
| Pressure | Push force | Pull force |
|---|---|---|
| 0.5 MPa | 628 N | 528 N |
| 0.7 MPa | 880 N | — |
| Max (@1.0 MPa) | 128 kgf | |
Cylinder thrust is separate from the lock's holding capability. Actual usable force is lower than theoretical due to friction and back-pressure — size with a margin.
Where the Airtac SAILB Rear Lock Cylinder SAILB40X75 Is Used
Vertical Power-Loss Safety
Secures lifted loads in the retracted position instantly if air pressure drops, preventing sudden crashes on vertical actuators.
End-of-Stroke Clamping
Holds a workpiece firmly at the rod-in stroke terminal without consuming continuous compressed air, saving energy.
Gate and Guard Holding
Keeps safety gates and machine guards locked closed in the retracted state until the release air is actively supplied.
Is the Airtac SAILB Rear Lock Cylinder SAILB40X75 the Right Lock Cylinder?
Choose this 40mm bore if your application requires up to 879N of thrust at 0.7 MPa; stepping up to a 50mm bore provides 1374N if your load demands more force. Select the SAILB configuration when the load must be held in the retracted position, and choose SAILF if it must be held extended. If your process requires clamping at an arbitrary mid-stroke point rather than a stroke end, the BSAI clamp-lock cylinder is the correct choice instead.
When integrating this cylinder, avoid using fast-exhaust valves, as back-pressure on the locker side can inadvertently release the lock; an independent-exhaust solenoid valve is required. The lock provides a static hold after the rod stops, rather than acting as a dynamic brake for a moving rod. For replacements, verify the 75mm stroke, PT tapered port threads, carbon steel rod, and your required mounting style from the Basic, FA, FB, CA, CB, CR, LB, TC, FTC, TCM1, or TCM2 options. If position sensing is needed, note this unit lacks a magnet and requires the -S option for CMSE reed or DMSE electronic sensors.
Quick checklist
- ✓ Hold needed at the retracted (rod-in) end?
- ✓ Or lock anywhere → use BSAI
- ✓ Independent-exhaust valve fitted
- ✓ Port/thread type (PT/G)
- ✓ Extra safety measure for people
Airtac SAILB Rear Lock Cylinder SAILB40X75 FAQ
At an operating pressure of 0.5 MPa, the 40mm bore provides 628N of push force and 528N of pull force. At 0.7 MPa, the push force increases to 879N.
The lock is spring-applied and air-released, engaging only at the retracted stroke end in the back cover. It provides a static hold after the cylinder stops, and is unlocked by supplying air to the release port or using the manual lever.
Related AirTAC Lock & Standard Cylinders
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